Table-lock.



E. L. MARSTON.

TABLE LOOK.

'APPLIOATION FILED Am. 17, 1911.

Patented Dec. 30, 1913.

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TABLE LOOK. APPLICATION FILED APB-.17, 1911f Patented Dec. 30, 1913.

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EDGAR I. MARSTON, 0F SOMERVILLE, MASSACHUSETTS, ASSIGNOR 'IO CHARLES J.

BROWN, 0F NEWTON, MASSACHUSETTS.

TABLE-LOCK.

i,o82,88a.

Specification of Letters Patent. Application filed April 17, 1911.

To all whom it may concern:

Be it known that I, EDGAR L. MARsToN, of Somerville, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Table-Locks, of which the following 1s a specification.

This invention relates to extension tables, and its object is to provide improved looking mechanism for drawing together the two top sections. In addition to the means for drawing together merely the two top sections, the invention includes means attached to each of the several extension leaves for forming connection between the locking devices on the top sections, whereby lockmg connection may be made between the top sections through as many extension leaves as may be interposed.

The mechanism in which the invention is embodied comprises an operating rod attached to the underside of one top section, means for operating the rod, and an abutment on the other top section, said operating rod being provided with-a catch adapted to engage said abutment to draw the sections together. The operating rod has two movements,one for drawing the sections together, and another for causing the catch member thereon to move laterally to and from the line of engagement with the abutment. When the operating rod is moved to release the abutment, it is also moved laterally out of the line of engagement so that it will not stand in the path of the abutment when the top sections are drawn apart. Each extension leaf is provided with an extension rod in many respects similar to the operating rod. Each extension rod is provided with a catch at one end and an abutment at the other end. Each extension rod is likewise provided with means for guiding the catch member to and from the line of the adjacent abutment with which it cooperates. Each extension rod is further provided with spring-tension means normally tending to move the catch member out of the line of engagement with'the adjacent abutment so that the extension leaves may be readily detached or separated when the operating rod is disengaged from its abutment.

Of the accompanying drawings which illustrate the preferred form of the invention Figure 1 represents a longitudinal vertical section of the top of an extension table provided with the locking mechanism hereinafter described. Fig. 2 represents a view similar to Fig. 1, with the addition of extension leaves interposed between the top sections. In this figure the locking mechanism is in locked position, whereas in Fig. 1 the locking mechanism is in an intermediate position. Fig. 3 represents a portion of the structure shown in Fig. 1, with the locking mechanism in completely locked position. Fig. 4 represents an inverted plan view, on a larger scale, of the mechanism as shown by Fig. 3. Fig. 5 represents a top plan view of a part of the mechanism attached to one of the extension leaves. Fig. 6 represents a side elevation of the same mechanism in inoperative position. Fig. 7 represents a side elevation of the same mechanism in an intermediate position. Fig. 8 represents a side elevation of the same mechanism in operative position. Fig. 9 represents a side elevation of a part of the operating rod in locked engagement with the abutment of an extension rod. Fig. 10 represents a view, s1m1lar to Fig. 9, of

the locking mechanism in inoperative position.

The same reference characters indicate the same parts wherever they occur.

The two top sections of the extension table are indicated respectively at 10 and 10*. The usual slides for connecting said top sections are indicated as a whole at 11. The slides are mounted upon a suitable pedestal which may be solid or which may consist of separable sections. The table illustrated has separable pedestal sections 12 and 12*.

The mechanism for drawing together the two top sections without interposed extension leaves, comprises an operating rod 15 having a catch member 16, an operating handle 17 pivotally connected to one of the top sections, and an abutment 18 on the other top section for engagement by the catch 16. All of the aforesaid elements are attached to the under side of the top sections so as to be entirely concealed when the sections are closed.

The operating handle 17 is movable about a pivot 19 which is supported by a bracket 20 secured in any suitable manner to the top section. The operating rod is connected with the handle 17 through yielding connection hereinafter described and an adjustable connection consisting of a screw-threaded rod 21 and a clevis 22. The rod 21 is threaded in the clevis, and the latter is pivotally connected at 23 with the handle 17. The yielding connection between the rod 15 and the handle 17 comprises a strip 24: of sheet metal bent in the form of a letter U, a crossbar connecting the ends of the same with the rod 21, a plate 26 carried by the rod 15, and a helical spring 27 compressed between the plate 26 and the intermediate portion of the strip 24. The rod 15 extends through said intermediate portion, and is adapted to slide therein, while the ends E26 of the plate 26 are reduced and arranged to slide in slots 28 in the strip 24:. The operating rod 15 is supported between the aforesaid yielding connection and the catch member 16 by a lever 30 whose function is to guide the catch member laterally to and from the line of engagement with the abutment 18 or a similar abutment. The lever 30 is arranged upon a pivot stud 31 projecting from a bracket 32 affixed to the top section 10. The pivot stud 31 is the fulcrum about which the lever 30 swings, and at some distance from said fulcrum is a stud 33 connecting the lever with the operating rod. The stud 33 is affixed to the lever and occupies a slot 34: in the operating rod. The lever 30 has a second fixed stud at 35 which with the stud 33 as hereinafter explained. The stud 35 coacts with faces 36 and 37 of the rod. The face 36 is parallel to the slot 34, and the face 37 is inclined and is in effect a cam. In providing the face 37, a suitable notch is formed in the rod for the reception of the stud 35. A spring 38 is attached to the stud 35 and to a pin 39 on the operating rod. The spring tends to retract the rod to inoperative position, and to swing the lever about its pivot 31.

When the rod is retracted to inoperative position the stud 35 occupies the notch and the catch is below the line of engagement; but when the rod is drawn by the handle to operative position, the face 37 rides up on the stud 35. This not only raises the rod, but, through the medium of the stud 33, swings the lever 30 and raises the stud 35. The upward movement of the stud 35 augments the upward movement of the rod so that the catch 16 is thrown quickly into the acts in conjunction line of engagement. WVhen the stud 35 passes from the inalined face 37 to the face 36, upward movement of the rod ceases and thereafter the rod moves substantially lengthwise. As soon as the stud moves on to the face 36 the link is locked in its raised position by the conjoint action of the studs 33 and 35 and that portion of the rod between them. The face 3A3 is parallel to the face 36 so that the rod may continue to move lengthwise after being raised. The tension of the spring 38 tends to hold the lever so that the studs 33 and 35 will not bind upon the faces 34* and 36. This tension is so far decreased, when the operating rod is moved backward, as to permit the lever to swing downwardly as the notch in the rod moves into register with the stud 35.

The coperative actions of the rod and lever may be summarized as follows :-The rod raises itself on the stud 35 and simulta neously raises the stud. This in turn is transmitted back to the rod, increasing the rise thereof. At the completion of upward movement the lever becomes locked by the rod, and by the same action the rod is held by the studs in the line of engagement but is nevertheless free to move lengthwise in said line. An important point concerning the arrangement of the lever is that very little drawing movement of the rod is wasted in moving the catch into the line of engagement. The initial movement of the studs 33 and 35 is almost squarely toward the line of tension of the rod.

As previously stated, the invention includes extension rods attached to extension leaves in such manner as to form connection between the operating rod and the abutment 18. As shown by Fig. 2, two extension leaves A and B are interposed. Each leaf has mounted on its under side an extension rod 15*. Each extension rod has at one end a catch member 16*, and at the other end an abutment 18*. The extension rods are adapted to slide upon guide straps 10 affixed to the under sides of the leaves, and they are otherwise mounted on levers precisely the same as which the operating rod is mounted. The details of construction of the extension rods and the guiding means therefor are shown by Figs. 5 to 8 inclusive. The slots 34: in the extension rods are shown somewhat shorter than the slot 34- in the operating rod. This is because the extension rods do not have to move as far as the operating rod in order to complete the connection throughout the series of rods.

The mode of operation when extension leaves are interposed is as follows: When the leaves are laid upon the slides 11, the several catch members are below the line ment with the several abutments.

lVhen the that described and on of engagea handle 17 is moved to locking position, the catch 16 on the operating rod is the first catch of the series to engage its cooperative abutment. The catch 16, after moving upwardly into the line of engagement, moves horizontally, drawing with it the extension rod '15 of the leaf A. As the operating rod continues to move, by reason of its slot 34:, the catch member 16 of leaf A moves upwardly into the line of engagement with the abutment of leaf B. The operating rod and the first extension rod thereafter continue to move horizontally until the catch 16* of leaf B has been moved upwardly and horizontally against the abutment 18 on the remote top section 10*. The draft of the operating rod is thus transmitted to the abutment 18, and the two top sections are drawn together against the interposed extension leaves. When the several rods and abutments are positively engaged so as to prevent all further movement of one with relation to another, the remainder of the movement of the handle 17 is taken up by the spring 27. When the handle 17 is depressed to release the several locking rods, they are automatically retracted by their individual springs 38 so as to be withdrawn from the line of engagement. The connecting elements on the several extension leaves are identical in construction and are therefore interchangeable. Any desired number of leaves may be interposed, and the connecting elements thereon will be connected progressively when the handle 17 is operated, until the whole number of rods in the series become connected.

I claim: 7

1. A table lock comprising an operating rod having an inclined face, a catch on said rod, means on one of the table sections for moving said rod longitudinally, an abutment on the other table section adapted to be engaged by said catch for drawing the sections together, a member pivotally mounted on one of the table sections for effecting lateral movement of the rod, means on said member in eccentric relation to the axis of said member for coacting with said inclined face to efiect lateral movement of the rod when said rod is moved longitudinally, and means connecting said rod and said pivotal member for swinging the latter to impart movement to said eccentric means to augment the lateral movement of the rod. 7

2. A table lock comprising an operating rod having an inclined face, a catch on said rod, means on one of the table sections for moving said rod longitudinally, an abutment on the other table section adapted to be engaged by said catch for drawing the sect-ions together, a member pivotally mounted on one of the table sections for effecting lateral movement of said rod, means on said member in eccentric relation to the axis of said member for coacting with said inclined face to effect lateral movement of the rod when said rod is moved longitudinally, and means on said pivotal member having sliding engagement with said rod for transmitting lateral movement of the rod to the pivotal member said transmitting means being adapted to move said eccentric means so as to augment said lateral movement.

3. A table lock comprising an operating rod having two oppositely disposed longitudinal faces and an inclined face meeting one end of one of said longitudinal faces, a catch on said rod, an abutment on one of the table sections adapted to be engaged by said catch, means on the other table section for moving said rod longitudinally to draw the sections together, and a lever mounted on one of the table sections for causing said rod to move laterally to and from its operative path, said lever having means engaging said faces of the rod whereby the rod is moved laterally to and guided in said path, and whereby the said lever is moved to augment the lateral movement of the rod.

4. A table lock comprising an operating rod having a catch, an abutment on one of the table sections adapted to be engaged by said catch, means on the other table section for moving said rod longitudinally to draw the sections together, and a lever for causing said rod to move laterally to and from its operative path, said lever being mounted on one of the table sections and having projections extending laterally, said rod having faces adapted to move on said projections and to effect lateral movement of the rod to its operative path, said faces being adapted to efi'ect movement of the lever to augment lateral movement of the rod, and to permit independent longitudinal movement of the rod when the rod is in its operative path,

5. A lock for extension tables, comprising a rod movably mounted on one table section, an abutment on the other table section, said rod having a catch adapted to coact with said abutment when the sections are closed, each extension leaf having a rod provided with a catch any one of which is adapted to coact with said abutment, each leaf rod having an abutment adapted to be engaged by any one of said catches whereby all of said rods may be connected in a series from one table section to the abutment on the other section, yielding means for normally holding said catches out of the path of said abutments, means on said first table section for moving the first rod longitudinally, devices pivotally mounted on said first table section and said extension leaves respectively for cooperating with said rods, said devices and rods having coactive surfaces for moving said catches laterally in consequence of longitudinal movement of said rods, said rods and devices having other connections for transmitting lateral movement of said rods to cause angular movement of said devices about their pivots, such angular movement reacting through said coactive surfaces to augment the lateral movement of said catches whereby the latter are adjusted for cooperation with said abutments, said rods being capable of further longitudinal move- 10 ment to draw said sections together after said catches have been adjusted as aforesaid.

In testimony whereof I have atfixed my signature, in presence of two witnesses.

EDGAR L. MARSTON.

Witnesses a W. P. ABELL, P. W. PEZZETTI.

Copies of this patent may be obtained for five cents Each, by addressing the Commissioner of latents,

Washington, D. C. 

